Quantitative Microbial Risk Assessment for Sustainable Water Resources
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Quantitative microbial risk assessment for sustainable water resources A Thesis Submitted to the Faculty of Drexel University by Kerry Ann Hamilton in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2016 © Copyright 2016 Kerry Ann Hamilton. All Rights Reserved. iii Dedication For Nick, my parents, and my brother Mark. iv Acknowledgement First I would like to thank my advisor, Dr. Charles Haas for encouraging me on my path to pursue an engineering degree and allowing me tremendous freedom to pursue projects I am passionate about at the nexus of environmental engineering and public health. He has been extremely patient and provided many opportunities for me to grow as a researcher and person over the past five years. I am extraordinarily grateful for his expert mentorship and support during this time. This work was greatly enriched by my committee members Dr. Patrick Gurian, Dr. Mira Olson, Dr. Franco Montalto, Dr. Mark Weir, and Dr. Christopher Sales. Their expertise has greatly improved the methodology and insights of this work, and they have provided generous feedback throughout this journey. I would like to extend a special thanks to the Australian-American Fulbright Commission and my Fulbright host laboratory at the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO). Additionally, I am especially grateful for my mentors Dr. Simon Toze and Dr. Warish Ahmed for giving me many opportunities, intensive laboratory training, and leveraging funding support to conduct a large study of roof-havested rainwater tanks as a visiting member of their research group. Additionally, CSIRO group members Leonie Hodgers, Andrew Palmer, Kylie Smith, Dr. Pradip Gyawali, Dr. Jatinder Sidhu, and numerous other CSIRO staff have aided significantly in both logistical and technical aspects of this work and I am greatly appreciative of their efforts. I am also very thankful to numerous employees of the Ecosciences Precinct in Brisbane, Australia as well as residents at the Currumbin Ecovillage for generously allowing me to sample their rainwater tanks. Their insightful questions and feedback improved the survey methodology and interpretation of the results greatly and this work could not have been performed without their voluntary participation. Tremendous thanks are due to the Haas lab collaborators on the Legionella risk management project at American Water, Dr. Mark LeChevallier, Dr. Patrick Jjemba, and Mr. William Johnson for their microbiological insights, patience, and help in developing our risk assessment model. v I would like to thank my fellow researchers in the Haas lab group current and former: Bidya Prasad, Dr. Michael Ryan, Dr. Neha Sunger, and Dr. Sandra Teske. Specifically I would like to thank Dr. Ryan for introducing me to the process of risk modelling and helping to trouble-shoot models and laboratory experiments throughout my time at Drexel and Bidya Prasad for her modeling expertise and extraordinary caring and willingness to help with any project. I would also like to thank my fellow graduate students current and former including Kaitie Sniffen, Anita Avery, Dr. Kimberley DiGiovanni, Stephen White, Dr. Kimberlee Marcellus, Dr. Noura Abualfaraj, Dr. Megan Hums, Doug Goetz, Bita Alizadehtazi, Dr. Somayeh Yoosefi, Dr. Qasideh Pourhashem, Dr. Raquel Catalano de Sousa, and Yetunde Sorunmu for their support and encouragement. Thank you to Drexel Graduate Women in Science and Engineering founder Dr. Josa Hanzlik and board members Deeksha Seth, Dr. Marissa Powers, Val Tutwiler, and Dr. Kristyn Voegele for their leadership and support to create opportunities for graduate students and greatly enriching the graduate experience for myself and others. Thank you to graduate and administrative staff Barbara Interlandi, Kenneth Holmes, Sarah Collins, Sharon Stokes, Kim Spina, Teck-Kah Lim, and especially Taz Kwok for always coming to the rescue many times throughout the past five years and streamlining the graduate school process. Thank you to Dr. Robert Brehm for encouraging me to take the F.E. exam and helping me throughout the preparation process. Thank you to Jay Bhatt and the library staff for their help during our extensive literature review process and numerous article requests. I would like to acknowledge the funding opportunities provided to me throughout this research from WateReuse Research Foundation grant WRF-05 and the Fulbright-CSIRO Postgraduate Scholarship from the Australian-American Fulbright Program. Additionally, I have received generous support from Drexel University through the Drexel Provost Graduate Fellowship, the Drexel George Hill Jr. Fellowship, the Steven E. Giegerich Memorial Scholarship, the Drexel Higher Education Advocate Travel Award, the Marilyn A. Burshtin Memorial Award, and the Claudio Elio Memorial Fellowship in Environmental Science & vi Environmental Engineering. The Society for Risk Analysis has supported my work through the dose response group annual meeting student merit award. Finally, and most importantly, I would like to acknowledge my friends and family for their support. My husband, best friend, and sampling assistant Nicholas Preston has provided me with endless faith, patience, and support. My brilliant mom and dad have sacrificed many things in their lives to provide me with every opportunity to pursue my dreams. Thank you to my extraordinary brother Mark for inspiring me to always learn new things, and for his patience and technical coding ingenuity throughout the Legionella reclaimed water project. Thank you also to Nanny, Aunt Lois, Uncle John, Michael, Danielle, Nicole, Steven, Aimee, Michele, and Joe for your unwavering support and sense of humor. Cassandra and Alison thank you for helping me plan a wedding and continuing to be my best friends even throughout a very busy PhD program. Finally, thank you to mom and dad Preston, Anthony, Vince, and Devon for your support. To all of you—thank you will never be enough. vii Table of Contents Table of Contents ..................................................................................................................... vii List of Tables ........................................................................................................................... xii List of Figures ..........................................................................................................................xvi Abstract .....................................................................................................................................xx 1. Introduction ........................................................................................................................ 1 1.1. Background ................................................................................................................ 1 1.2. Research Objectives ................................................................................................... 3 1.2.1. Objective 1: Prioritize pathogens previously quantified in harvested rainwater for further study ........................................................................................................................... 3 1.2.2. Objective 2: Conduct a screening of Brisbane rainwater tanks for pathogens ....... 3 1.2.3. Objective 3: Conduct a seasonal study of Brisbane rainwater tanks for pathogens 4 1.2.4. Objective 4: Develop a dose response model for the Mycobacterium avium complex (MAC) ..................................................................................................................... 4 1.2.5. Objective 5: Assess the health risks of Legionella and MAC in harvested rainwater 5 1.2.6. Objective 6: Assess the health risks of Legionella in reclaimed water .................. 5 2. Prioritization of pathogens in harvested rainwater ............................................................ 7 2.1. Roof-harvested rainwater ........................................................................................... 7 2.1.1. Introduction ........................................................................................................ 7 2.1.2. Human health Risks ........................................................................................... 8 2.2. Pathogens identified for further study ...................................................................... 17 2.2.1. Legionella pneumophila ................................................................................... 17 3. Screening study of Brisbane roof-harvested rainwater tanks for opportunistic pathogens 25 3.1. Abstract .................................................................................................................... 25 3.2. Keywords: ................................................................................................................ 26 3.3. Introduction .............................................................................................................. 26 3.4. Materials and methods ............................................................................................. 29 3.4.1. Study areas and survey ..................................................................................... 29 3.4.2. Tank water sampling ........................................................................................ 30 3.4.3. Enumeration of fecal indicator bacteria (FIB) ................................................. 30 3.4.4. Concentration of rainwater samples ................................................................